Fundam. appl. Nematol., 1995,18 (4), 391-392

Short note

INFLUENCE OF TEMPERATURE ON IN VITRO REPRODUCTION OF PRATYLENCHUS COFFEAE, P. GOODEYI, AND RADOPHOLUS SIMILIS

Jorge PINOCHET *, Carolina FERNANDEZ * and Jean-Louis SARAH ** * Departamento de Patologia Vegetal, IRTA, Crta. de Calrrils sin, 08348 Ca!nüs, Baree/ona, Spain, and ** CIRAD-FLHOR, B.P. 5035, 34032 Montpellier Cedex 1, France. Accepted for publication 12 September 1994. Key-words: Pratylenehus coJfeae, P. goodeyi, Radopholus similis, reproduction, temperature.

The migratory endoparasitic Pralylenehus 30 s (three 10 s periods separated by 5 s intervals). The eoffeae, P. goodeyt~ and Radopholus similis are the species suspension was passed through 150 J..Lm-pore sieves of major concern in ( MA), and plantain (100 mesh) and twice through the 25 J..Lm sieve (Musa AAB and ABB) production throughout the (500 mesh). Carrot root tissue and debris collected on world (Tarte & Pinochet, 1981; Gowen & Quénéhervé, the 150 J..Lm sieve were discarded. The different devel­ 1990). The burrowing , R. similis) is consid­ opmenral stages ofeach nematode species were counted ered the most damaging of the three species; it is wide­ under the compound microscope based on 1 ml aliquots spread in the hot and humid tropics. Pralylenehus coffeae in a low volume of suspension. Final nematode popu­ is found in a wider range of hosts and environmenrs, lations were analyzed by an ANOVA. Data were loglo whereas P. goodeyi appears to be common in cooler transformed (x + 1) for analysis. Means were compared subtropical and highland environmenrs, mainly East by Tukey's multiple range test (P ~ 0.05 and 0.01). and Central Africa (Bridge, 1988). P. goodeyi is also considered an important nematode pest of in the Canary Islands, Cyprus, Crete and Taiwan (Stover Results and discussion & Simmonds, 1991). The purpose of the present in­ Pralylenchus goodeyi reproduced significantly more at vestigation was to measure the reproduction of three 21 oC than at 16 oC, although no differences were found important Musa attacking nematodes at a low, medium and high temperature regime under monoxenic condi­ between 21 oC and 25 oC (Table 1). Reproduction ofP. tions. coffeae differed significantly at each of the three estab­ lished temperatures. At 16 oC this species barely mul­ tiplied. Optimum population increase was recorded at Material and methods the high temperature regime. A similar pattern was ob­ Pralyleluhus goodeyi and R. similis were obtained from served with R. similis) although in this case no eggs, banana Musa MA in Tenerife, Canary Island, and An­ juveniles or males were found at 16 oC suggesting that guédédou, Ivory Coast, respectively. P. coffeae was origi­ reproduction did not occur. The females of R. similis nally isolated from roots in Retalhuleu, recovered (five specimens) seem to be survivors from Guatemala. The isolates were reared moxenicaUy on the initial inoculum. This indicates that this temperature carrot (Daueus carola) disc cultures (Moody el al.) 1973) is within the limits of nematode survival and insufficient and incubated at 23-24 oC for two to three generations. for nematode reproduction. Highest population build­ Nematode inoculum was recovered from cultures, sur­ up for R. similis was obtained at 25 oc. Comparative face sterilized with 2000 ppm ofstreptomycin sulfate for reproduction between the three species clearly indicates 3 h followed by three rinses in sterile water prior to the P. goodeyi multiplies significantly more at a lower tem­ inoculation of carrot sections cv. Nantesa. Each carrot perature and considerably less at 25 oC than P. coffeae section weighing approximately 2.5 g was placed in a and R. similis (Table 1). There were no differences in 5 cm-diam. Petri dish. Ten gravid females from each the reproduction between the three nematodes at 21°C. isolate were inctividually collected with a micropipette In relative terms, the population build-up of P. goodeyi and delivered to the surface of a carrot section in 0.1 ml was far below those of the two other species. An expla­ water suspension. Three sets of ten cultures per isolate nation could be that P. goodeyi)s intrinsic multiplication were prepared and kept in three incubators at 16,21 and rate is really lower than the other species, or that P. 25 (± 0.5) oC for 75 days. At the end ofthis period, both goodeyi has a very sharp thermal optimum that was not nematodes and carrot culture were recovered from the measured in the experimenr (temperatures between 17 Petri ctish and macerated in a biender at 14500 rpm for to 20 oC, and 22 to 24 OC). On the other hand, carrot

ISSN 1164-5571/95/04 S 4.00/ © Gauthier-Villars - ORSTOM 391 J. Pinoche1 et al.

Table 1. Reproduclion ofPratylenchus goodeyi, P. coffeae, and Radopholus similis al 16, 21 and 25 oC in monoxenic carroi cullUres 75 days afler inoculalion wùh Un gravid females.

Nematode Temp. Nematode developmental stages (%) Final (oC) population Eggs Juveniles Males Females

P. goodeyi 16 34 (19)* 77 (42) 4 (2) 68 (37) 183 a C** 21 75 (9) 638 (74) 63 (7) 88 (10) 864 b A 25 138 (32) 250 (59) 0 (0) 38 (9) 426 ab A P. coffeae 16 15 (27)* 12 (22) 3 (5) 25 (46) 55 a B 21 71 (15) 163 (34) 99 (20) 152 (31) 485 b A 25 3 830 (31) 5530 (45) 1 312 (10) 1 728 (14) 12400 c B R. similis 16 o (0)* o (0) o (0) 5 (100) 5a A 21 547 (21) 1 469 (55) 116 (4) 536 (20) 2668 b A 25 15250 (36) 19700(46) 1 558 (4) 5907 (14) 42415 cb B

• Values in paremheses are percentages of the total population. *' Means in COlUITUl for each isolate followed by the same lerter do not differ according to Tukey's tesl CP < 0.01). Low case lerters . differences belWeen lemperarure for the same nemalode; upper case lerters : differences belWeen nemalodes al the same lemperarure : left coluITUl : 16 oC; cencral column : 21°C; righl column: 25 oc. disc might not have been an ideal medium for multipli­ Acknowledgements cation, as it is for R. similis and P. coffeae. The authors than!< Drs. ]. G. Baldwin and M. Mundo­ The low and high temperature requirements for P. Ocampo for their taxonomic assistance. goodeyi and R. similis, respectively, have been docu­ mented mainly based on monitoring populations at dif­ References ferent altitudes in Rwanda (Sarah, 1989) and Cameroon BRlDGE,]. (1988). Plant nemarade pests of banana in East .(Bridge et a!., 1995). However, the temperature require­ Africa with particular reference ra Tanzania. NemalOdes and ments, especial1y the minimum levels, for the devel­ Ihe bore weevil in bananas : presem SIGIUS of research and OUI­ opment of each of these nematodes species were un­ lock. Proc. Worksh., lm. Network Improv. Banana & Plamain known. These results substantiate the previous (INIBAP), Burundi, 7-11 Dec. 1987.35-39. observations and indicate that R. similis does not persist BRlDGE, L PRlCE, N. S. & KOF1, P. (1995). Plant parasitic in temperatures below 16 oC or perhaps, even slightly nematodes of plantain and other crops in Cameroon, West higher than 16 oc. On the other hand, both Pratylenchus Africa. Fundam. appl. NemalOl., 18: 251-260. species appear to adapt to a wider range of temperatures GOWEN, S. & QUÉNÉHERVÉ, P. (1990). Nematode parasites in which P. coffeae shows a preference for temperatures of bananas, plantains and abaca. In : Luc, M., Sikora, R. & around 25 oC similar to that required by R. similis. Opti­ Bridge,]. (Eds), Parasùic nemalOdes in sublropical and Iropi­ mum temperature for P. coffeae development appears to cal agricullure. WalI.ingford, UK, CAB International, Insti­ be wel1 over 25 oc. On (Citrus jambhin), optimum tute of Parasiralogy : 431-460. reproduction occurred at 29.5 oC (Radewald el al., MOODY, E. H., LOWNSBERY, B. F., & AH"V1ED,]. M. (1973). 1971). In this study, nematode reproduction was not Culture of the rootlesion nematode Pralylenchus vulnus on measured above 25 ± 0.5 oc. carrot disks. J. NemalOl., 5 : 225-226. It is noteworthy that R. similis is not present ID the Canary Islands where P. goodeyi is widespread on ba­ RADEWALD, ]. D., O'BANNON, H. O. & TOMERLlN, A. T. (1971). Temperarure effects on reproduction and patho­ nanas. It is likely that the burrowing nematode has been genicity of Pralylenchus coffeae and P. brachyurus and surviv­ introduced through infested rhizomes (seed material) al of P. coffeae in roots of CÙms jambhiri. J. Nematol., 3 : brought in from Central America or Africa this century, 390-394. but the cooler temperatures that prevail in the Canary Islands, especial1y from December to April, have prob­ SARAH, ]. L. (1989). Banana nematodes and their conrrol in ably prevented its survival. P. coffeae is also present ID the Africa. Nemalropica, 19: 199-216. Canary Islands, although its occurrence is rare. Ir could STOYER, R. H. & SIM.MONOS, N. W. (1991). Bananas. Essex, have been introduced from Central America where it is UK, Longman Scientific & Technical, 468 p. commonly found on bananas together with R. similis. TARTE, R., & PINOCHET,]. (1981). Problemas nemalOlOgicos The tolerance of P. coffeae to a wider range of temper­ del banano. Comribuci.ones recienles a Sil conocimiento y com­ atures, specially in the lower range (16 to around 20 OC) bau. Union Paises Exportadores de Banano (UPEB), Pana­ would expiain its survival in the Canary Islands. ma, 32 p.

392 Fundam. appl. Nemalol.